SiO<SUB>2</SUB> Content Retrieving and Metallogenic Factors Identification of a Granite-Type Uranium Ore-field Based on Thermal Infrared Data

Since the sensor of ASTER was launched,low-cost multi-spectral thermal infrared data were available.It injects energy to thermal infrared technology application on many fields.On the basis of analyzing the thermal infrared technology application potential on minerals and rocks,in this paper we apply this technology for extracting of information on granite-type uranium deposits.Taking the granite-type uranium deposits in south china as an example,based on thermal infrared data of ASTER,mosaic,radiometric calibration,atmospheric correction were made and the temperature and emissivity data were separated from the thermal infrared data.Then,we quantitatively retrieve SiO2 content in the rocks from emissivity data by inversion algorithm simulated from different band ratio combination.According to the inversion map view,we can't extract information of small-scale silicification alteration due to the spatial resolution limitation of ASTER thermal infrared data,but the map clearly shows many large silicified fault zones,the distribution area of acid-rocks and the red beds area that have highest content of the silica.What's more,the results conform to the geological facts and they are validated in the field.Above all,the practice proves that information mining technology of thermal infrared data will play an important role in the extraction and analysis of the metallogenic essential factors even in the prospecting target of granite-type uranium deposits.